Electric switch



(No Model.) I 3 Sheets-Sheet 1.

A. STROMBERG.

ELECTRIC SWITCH. @0. 493,369. Patented Mar. 14, 1893.

QyrWamZeg M7 41- 3 MW (No Model.) 3 sheetssheet 2, A. STROMBERG. ELECTRIC SWITCH.

No. 493,369. Patented Mar. 14, 1898.

(No Model.) 3 Sheets-Sheet 3. A. STROMBERG, ELECTRIC SWITCH.

Patented Mar. 14, 1893.

w: uoums PETERS c0, PHOTO-LIT UNITED STATES PATENT OFFICE.

ALFRED STROMBERG, OF CHICAGO, ILLINOIS.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 493,369, dated March 14, 1893.

Application filed November 1, 1892.

To all whom it may concern.-

Be it known that I, ALFRED STROMBERG, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Electric Switches, (Case No. 6,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

M y invention relates to electric switches which are employed in burglar alarm systems, or in other electric signaling systems. It is designed more particularly to be used in connection with the system shown and described in my application Serial No. 425,268.

Referring to the accompanying drawings, Figure 1 shows an elevation of my switch. Fig. 2 shows a side view thereof. Fig. 3 shows a back View thereof. Fig. 4 shows in diagrammatic form the protected district and the switch of my invention included in the local alarm circuit. Fig. 5 is a similar diagrammatic illustration of the protected district, the switch of my invention being also included in the local alarm circuit, a slight modification being made in the arrangement of the circuits.

Like parts are indicated by similar letters of reference throughout all the views.

Referring to Figs. 1, 2 and 3, I have shown therein the switch in its idle position, the handle a being fastened upon a rod b, said rod being journaled upon an angular rod 0, said rod 0 being supported upon block (Z. Mounted upon block 01 are line springs e, e, as also are contact plates f, f. To the rod Z) is affixed a switch block b which impinges upon the line springs e or 6, according as the switch a is swung to the left or the right.

In Fig. 3 I have shown the position of the line spring e when the switch a is swung to the right, the said position being shown in dotted lines. Swinging the switch a to the left or to the right serves to break connection between the contact plate f or contact plate f, which are mounted upon the block d, and the line springs e or 6.

Referring to Fig. 4 I have shown the line springs of the switch connected in circuit at the central station. The calling key g, shown mounted upon the lower portion of the block g in Figs. 1 and 2, is placed in the circu t Serial No. 450,642. (No model.)

from the protected district, through the relay at central station to ground. During the time that the subscribers district is protected it may be desired to signal said subscriber. In such a case to prevent the local alarm from being unnecessarily sounded switch a is swungtotheleft,breakingcircuitatt. When the switch a is so turned, calling key g is depressed so as to close the circuit from ground 2 through the battery it, through said calling key g to the alarm bell Z at the subscribers station, through the protected district m to ground at n. The subscriber upon receiving the signal, answers by depressing the key 0 which breaks the circuit to the central station, thereby de-energizing the magnet 19, allowing the armature lever q to fall and complete circuit at 9, through line spring 6 which has been allowed to assume its normal position,individual annunciator s and alarm hell 8', battery 3 thence back to r by lever g.

If during the day it is desired to signal the subscriber, calling key g is depressed, which completes the circuit from ground 2' to battery 70, from battery 7a, through switch, alarm bell Z, and the subscribers switch 75 which has previously been swung upon button 15 to ground The subscriber responds by depressing the key 0, which breaks the circuit from the protected district to central station. Now just previous to the depression of key 0 the circuit is complete from ground a, battery to, relay 1L2, key g, alarm bell Z, switch 25 to ground i Therefore when circuit is broken at 0 armature lever (1 falls and completes circuit through the alarm bells and individual annunciator 8, thus indicating to the operator that the subscriber has received the signal. The local circuit controlled by the relay 1) is adapted to be closed to sound an alarm when, for any reason, the circuit passing through the protected district is broken, the electromagnet of the relay is de-energized permitting the armature g to fall and close the local circuit. The local circuit controlled by the relay n is adapted to be closed when, for any reason, the resistance a is cut out of the circuit passing through the protected district. XVhen this resistance is cut out, as bya short circuit or ground, the electro-magnet of the relay a is sufticiently energized to attract the armature '22, thus closing the local circuit.

In Fig.5 I have shown the same apparatus ICC and circuit connections that I have shown in Fig. 4, with the exception that battery 70 is dispensed with.

During the time that the subscribers district is protected, if it is desired to send a signal to said subscriber, calling key g is depressed, which breaks the circuit at c, which causes the single stroke alarm bell o to sound, which alarm bell is used in place of the double stroke alarm bell Zshown in Fig. 4. The switch a is turned to the left breaking circuit at h before the operator sends this signal to the subscriber. The subscriber returns the signal asdescribed in connection with Fig. 4.

During the day when the subscriber has cut out his protected district by short circuiting the current from central station to ground at t", if it should be desired to signal said subscriber, the operator by breaking the circuit at 1) causes the single stroke alarm bell e at subscribers station to sound. The subscriber returns a signal by depressing key 0 which breaks the circuit from central station at 1%, which causes the magnet 19 to be deenergized, which results in completing the circuit at r through the alarm bell 8, thus giving the desired return signal. During the entire time that the protected district is short circuited the switch a must be in such a position as to break circuit at t in order to prevent the alarm bell a from being constantly rung. For, as described in Letters Patent No. 483,7 28, granted to me October 4, 1892, the resistance a at the subscribers station being cut out, when said subscriber places the switch upon button t the magnet 10 has its electro motive force increased sufficiently to attract the armature lever m, which causes circuit to be completed at a, through line spring e and alarm bell 10 individual annunciator u and battery 3 back to point a by the armature lever 10". Therefore in order to prevent the alarm s from constantly sounding circuit is broken at t. I have shown the switch of my invention thus connected in circuit with the system described in my application Serial No. 425,268, and also in Fig. 5 I have shown how with the use of my switch and a single stroke bell, the battery may be dispensed with, and all the essential results accomplished which are accomplished in the system shown in Fig. 4.

By the construction of my switch by which the lever a has four stops at which it is held in its revolution, I am enabled to place the circuits operated bysaid switch secu relyin the desired position, and at the same time by a glan ce at the switch to determine in what condition each circuit is.

Having thus described my invention,what I claim as new and desire to secure by Letters Patent, is

1. In an electric switch, the combination with contact springs normally resting against their contact points, of a shaft carrying upon one end a handle, a cam mounted upon said shaft between said springs and of a length greater than the semi-distance between said springs, said shaft adapted to be rotated, whereby one or the other of said springs may be lifted from its contact point, the end of said cam being adapted to fit said springs to hold the shaft in its new position, substantially as described.

2. In an electric switch, the combination with contact springs normally resting against their contact points and situated at the rear of the board, of a shaft passing through said board and carrying at its front end ahandle, a cam mounted upon said shaft between said springs and of alength greater than the semidistance between said springs, said shaft adapted to be rotated in either direction to lift one or the other of said springs from its contact, the end of the cam being adapted to fit the springs to hold the shaft in its new position; whereby the position of said handle may indicate the condition of the line as to electrical connection, substantially as described.

3. In an electric switch, the combination of a line spring 6 normally included in the circuit in which are the alarm hell 3, individual annunciator 5, battery 3 and armature lever q, with a line spring 6 normally included in the circuit in which are the alarm bell a individual annunciator a battery .9 and armaturelever a and battery It, adapted to ring the subscribers alarm belllwhen key g is depressed, together with a keyo included in the circuit from the subscribers station to central station; whereby the subscriber may signal the central station, substantially as shown and described.

4. In an electric switch, the combination of a line spring 6 normally included in the circuit in which are the alarm bell s, individual annunciator 5, battery 5 and armature lever q, with a line spring e normally included in the circuit in which are the alarm bell "a individual annunciator a battery 8 and armature lever a together with a key g included in circuit from the central station to the subscribers station; whereby when said key is depressed, the single stroke bell 4) included in the same circuit with said key g is caused to alarm the subscriber, a key 0 being provided whereby the subscriber may signal the central station, substantially as shown and described.

In witness whereof I hereunto subscribe my name this 29th day of October, A. D. 1892.

ALFRED STROM BERG.

Witnesses:

W. CLYDE J ONES, Gnoaen L. CRAGG. 

